Adaptive equalization techniques are commonly used in communication receivers, for example in order to improve Signal to Noise Ratio (SNR) or to reduce Inter-Symbol Interference (ISI). Turbo equalization is a special class of equalization techniques that adapt the equalizer based on feedback from a decoder. Turbo equalization techniques are described, for example, by Raphaeli and Saguy, in “Linear Equalizers for Turbo Equalization—A New Optimization Criterion for Determining the Equalizer Taps,” 2nd International Symposium on Turbo Codes and Related Topics, Brest, France, Sep. 4-7, 2000, pages 371-374, which is incorporated herein by reference.
Tüchler and Singer analyze Turbo equalizer performance, in “Minimum Mean Squared Error Equalization using A-Priori Information,” IEEE Transactions on Signal Processing, volume 50, no. 3, March, 2002, pages 673-683, which is incorporated herein by reference. Lee et al. describe a specific class of Turbo equalization algorithms, in “Switching LMS Linear Turbo Equalization,” Proceedings of the 2004 IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP 2004), Montreal, Canada, which is incorporated herein by reference. Yet another Turbo equalization technique is described by Choi et al., in “Adaptive Linear Turbo Equalization over Doubly Selective Channels,” IEEE Journal of Oceanic Engineering, 2011, which is incorporated herein by reference.